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Is it better to torque cylinder heads to spec cold or hot on a warm engine rebuild?
I always followed the manual and torqued cold on a Ford 302 last month, but then a senior tech told me he torques hot to account for expansion and I had to redo all my work after checking his way and finding 15 ft-lbs of difference - which camp are you in and what's your evidence?
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felixb2519d ago
Ngl you might be overthinking it. 15 ft-lbs of difference sounds like a sensor error or a torque wrench calibration issue, not some magic thermal expansion property. I've seen guys argue hot vs cold for decades and the cure always involves a good torque wrench and following the FSM. Your senior tech might be stuck in the old school "feel" method where they just guess half the time. Modern head gaskets and MLS designs are way more forgiving than the stuff from the 60s. Unless you're building a top fuel engine that sees 1500 degrees, torquing cold to spec is fine for 99% of street builds. If you're really that worried just re-torque after a heat cycle and move on.
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